The present invention relates to a modular cell elevator for use on a containership in combination with a spreader bar and crane to load containers onto and to remove containers from the containership. The present invention also relates to connectors which connect two adjacent containers together to enable the containers to be simultaneously lifted with a single spreader bar.
Containerships frequently store containers in cells within the hold of the ship. A cell is a vertical compartment, generally several decks high, extending from a container storage deck inside the ship upward to a cell hatch on the weather deck of the ship. Each cell is generally sized to accommodate the length and width of shipping containers, which are generally constructed in standard sizes, such as those sizes specified by the International Standards Organization (xe2x80x9cISOxe2x80x9d). The standard sizes are generally twenty feet, forty feet, and forty-five feet long.
Spreader bars, which are well known in the container handling industry, are the end effector of a crane used to xe2x80x9cpickxe2x80x9d and xe2x80x9cplacexe2x80x9d cargo containers or other such loads. Spreader bars are typically attached by suitable means such as cables or hooks to cranes of various types (e.g., gantry cranes, boom cranes, straddle cranes etc.) or the like in order to move the cargo which has been engaged by the spreader bar from one desired site to another. Spreader bars are used all over the world in military and commercial applications.
One particular application of spreader bars in the cargo handling industry is for loading and unloading cargo to and from ships either docked in port or in an offshore loading/unloading facility. Typically, to pick a container from a cell on a containership, a hatch on the top of the cell is opened, providing access for the spreader bar to be lowered into the cell to engage the top-most container in a vertical stack of containers in the cell. The spreader bar must be carefully lowered through the hatch. Despite mechanical gathers at the top of the cells, even the best of operators generally must make several failed attempts before finally entering the cell. Once the spreader bar is inside the cell and immediately above the container, the connecting mechanisms located at the four corners of the spreader bar must be connected with the mating mechanisms of the container to thereby fasten the spreader bar to the top of the container. The container must be carefully lifted up the cell and through the hatch and then transported to its off-loaded location. The process must be repeated to remove subsequent containers in the cell. Similarly, to place a container into a cell, the container must be connected to the spreader bar as described above, and then lifted over the open cell. The container must then be carefully lowered through the cell hatch and into the cell. The container must then be released from the spreader bar and the spreader bar must then be carefully raised through the cell and the cell hatch, and then transported to another container for placing into a cell. The lowering and raising of the spreader bar through the cell hatch and the cell is a delicate and time-consuming process.
Occasionally, twenty foot containers are loaded into cells which are sized for forty foot or even forty-five foot containers. To maximize space, two twenty foot containers are loaded length-wise adjacent to each other in a single cell so that the two twenty foot containers can be stored in a space generally used by a single forty foot container. A twenty foot spreader beam must make two trips into the cell to load and/or off-load the two adjacent containers. However, if forty foot containers are also being transported, the spreader beam or other transport mechanism used to transport the containers between the cell and the weather deck must be adjustable or two different sized spreader beams and/or other transport mechanisms must be used.
It would be beneficial to develop a transfer mechanism that would eliminate the need for the spreader bar to be required to be raised and lowered through the cell hatch and the cell. Such a transfer mechanism would increase productivity significantly because it would ease the task of picking and placing containers. Also, since the transfer mechanism would work in parallel with the crane and spreader bar, the transfer mechanism would eliminate the need for the spreader bar to enter the hatch, a major portion of the crane cycle, and greatly reduce the time required to load and/or unload a containership.
It would also be beneficial to develop a connector, used in pairs, that would connect adjacent ends of two twenty foot containers to structurally form a single forty foot container so that a single forty foot spreader bar and/or other transport mechanism can be used without having to use a twenty foot spreader bar and/or other transport mechanism. Use of the connector would decrease loading/unloading cycle time by transporting two containers during each cycle and greatly increase productivity.
Briefly, the invention is a modular cell elevator for transferring a container through a container cell mouth opening on a container ship, the frame having a central opening therethrough sufficiently large to pass a container fitting the cell vertically through the frame. The modular cell elevator comprises a frame mountable on a container cell in an open hold of the ship; a plurality of hoists mounted on the frame, the hoists being releasably engageable with at least one container so as to transfer the container in either vertical direction through the central opening between a first location proximal a mouth of the container cell and a second location below the frame in the container cell, and a plurality of supports on the frame releasably engageable with a container in the first location proximal the cell mouth so as to support the container in the first location separately from the hoists.
In another aspect, the invention is also a device to remotely connect a hoist to a cargo container in a vertical container cell comprising a cable having a first end and a second end, the first end being attached to the hoist; a roller attached to the second end of the cable, the roller being magnetically engageable with a vertical guide of the container cell located below the hoist, the roller guiding the connecting device along a length of the vertical guide between the hoist and a container located in the cell; a twist lock on the second end of the cable insertable into and being engageable with a corner fitting on the container; an actuator on the twist lock to engage the twist lock with the corner fitting; and a sensor located at the second end of the cable so as to sense the insertion of the twist lock into the corner fitting.
The invention is also a device to connect a first shipping container to a second, adjacent shipping container, the device being releasably connected to a hoist, the device disconnecting from the hoist upon engagement of the device with one of the first and second containers, the device comprising a carriage engageable with the one of the first and second containers to transport the connecting device from the hoist to a junction between the first container and the second container; a first coupler insertable into a first container corner fitting, the first coupler being rotatable between an unlocked position and a locked position in the first container corner fitting; a second coupler insertable into a second container corner fitting, the second coupler being rotatable between an unlocked position and a locked position in the second container corner fitting; an actuator operably connected to the first and second couplers to insert the first coupler into the first corner fitting and to lock the first coupler to the first corner fitting and to insert the second coupler into the second corner fitting and to lock the second coupler to the second corner fitting, respectively; and a sensor located to sense the first and second couplers being positioned to be insertable into the first and second corner fittings, respectively, the sensor providing a signal to the actuator to insert the first coupler into the first corner fitting and to lock the first coupler to the first corner fitting, and to insert the second coupler into the second corner fitting and to lock the second coupler to the second corner fitting.
The invention is also a method of transferring a container between a first location at a mouth of a container cell wherein a lower end of the container is engaged by a plurality of supports and a second location in the container cell of a container ship, the method comprising the steps of releasably mounting a frame on a container cell in an open hold; releasably connecting at least one hoist mounted on the frame to a container; transferring the container between the first location and the second location with the hoist; moving a plurality of supports on the frame between a container engaged and a container disengaged position; and releasing the at least one hoist from the container.
The invention is also a method of connecting a first container to a second, adjacent container, the method comprising the steps of releasably connecting a hoist to one of the first and second containers; releasing a device from the hoist to connect a first shipping container to a second, adjacent shipping container; transporting the device from the hoist to the other of the first and second containers such that the device extends over the first and second containers; and releasably connecting the device to the first container and the second container.